The invention relates in general to heated tip injectors and in particular to a method and apparatus for controlling heated tip injectors.
In general, a heated tip fuel injector comprises an electric heater in the fuel path within an injector valve body. Examples of heated tip fuel injectors are described in U.S. patent application Ser. No. 09/088,126 entitled "Method of Preheating Fuel with an Internal Heater" filed on Jun. 1, 1998; U.S. patent application Ser. No. 09/088,127 entitled "Fuel Injector with Internal Heater" filed on Jun. 1, 1998; U.S. provisional patent application serial No. 60/122,162 entitled "A Method of Using an Internally Heated Tip Injector to Reduce Hydrocarbon Emissions During Cold-Start" filed on Feb. 26, 1999; and U.S. Pat. No. 5,758,826. The aforementioned three U.S. patent applications and one U.S. patent are hereby expressly incorporated by reference.
U.S. patent application Ser. No. 09/088,126 describes an electronic circuit for driving a heated tip injector having a two-pin connector. The electronic circuit alternately drives the injector coil and heater. U.S. Pat. No. 5,758,826 discloses a heated tip injector having a connector with more than two pins, in particular, three pins. The present invention is a method and apparatus for controlling a heated tip injector having a connector with more than two pins.